Direct laser interference patterning of nonvolatile magnetic nanostructures in Fe₆₀Al₄₀ alloy via disorder-induced ferromagnetism
Fe₆₀Al₄₀合金中非挥发性磁性纳米结构的直接激光干涉图案通过无序诱导铁磁性
無秩序誘起強磁性を介したFe₆₀Al₄₀合金の不揮発性磁性ナノ構造の直接レーザー干渉パターニング
무질서 유발 강자성을 통한 Fe₆₀Al₄₀ 합금의 비휘발성 자기 나노구조의 직접적인 레이저 간섭 패턴화
Patrones de interferencia láser directa de nanoestructuras magnéticas no volátiles en aleación Fe₆₀Al₄₀ mediante ferromagnetismo inducido por desórdenes
Motif d'interférence laser directe de nanostructures magnétiques non volatiles dans un alliage Fe₆₀Al₄₀ via ferromagnétisme induit par le désordre
Прямое лазерное интерференционное построение нелетучих магнитных наноструктур в сплаве Fe₆₀Al₄₀ с помощью ферромагнетизма, индуцированного беспорядком
Philipp Graus ¹, Thomas B. Möller ¹, Paul Leiderer ¹, Johannes Boneberg ¹, Nikolay I. Polushkin ²
¹ Department of Physics, University of Konstanz, 78457 Konstanz, Germany
² Institute for Physics of Microstructures of RAS, 603950 GSP-105 Nizhny Novgorod, Russian
Current magnetic memories are based on writing and reading out the domains with opposite orientation of the magnetization vector. Alternatively, information can be encoded in regions with a different value of the saturation magnetization. The latter approach can be realized in principle with chemical order-disorder transitions in intermetallic alloys.
Here, we study such transformations in a thin-film (35 nm) Fe₆₀Al₄₀ alloy and demonstrate the formation of periodic magnetic nanostructures (PMNS) on its surface by direct laser interference patterning (DLIP). These PMNS are nonvolatile and detectable by magnetic force microscopy (MFM) at room temperature after DLIP with a single nanosecond pulse. We provide different arguments that the PMNS we observe originate from increasing magnetization in maxima of the interference pattern because of chemical disordering in the atomic lattice of the alloy at temperatures T higher than the critical temperature Tc for the order (B2)-disorder (A2) transition.
Theoretically, our simulations of the temporal evolution of a partially ordered state at T > Tc reveal that the disordering rate is significant even below the melting threshold. Experimentally, we find that the PMNS are erasable with standard thermal annealing at T < Tc.